This invention relates to a process and apparatus for making aqueous hydrocarbon fuel compositions. The invention also relates to stable aqueous hydrocarbon fuel compositions. The process and apparatus are suitable for dispensing the fuels to end users in wide distribution networks.
Internal combustion engines, especially diesel engines, using water mixed with fuel in the combustion chamber can produce lower NOx, hydrocarbon and particulate emissions per unit of power output. However, a problem with adding water relates to the fact that emulsions form in the fuel and these emulsions tend to be unstable. This has reduced the utility of these fuels in the marketplace. It would be advantageous to enhance the stability of these fuels sufficiently to make them useful in the marketplace. Another problem relates to the fact that due to the instability associated with these fuels, it is difficult to make them available to end users in a wide distribution network. The fuels tend to break down before they reach the end user. It would be advantageous to provide a process and apparatus that could be used for blending these fuels at the dispensing site for the end user and therefore make the fuels available to end users in wide distribution networks.
This invention provides for a process for making an aqueous hydrocarbon fuel composition, comprising: (A) mixing a normally liquid hydrocarbon fuel and at least one chemical additive to form a hydrocarbon fuel-additive mixture; and (B) mixing said hydrocarbon fuel-additive mixture with water under high-shear mixing conditions in a high-shear mixer to form said aqueous hydrocarbon fuel composition, said aqueous hydrocarbon fuel composition including a discontinuous aqueous phase, said discontinuous aqueous phase being comprised of aqueous droplets having a mean diameter of 1.0 micron or less. A critical feature of this invention relates to the fact that the aqueous phase droplets have a mean diameter of 1.0 micron or less. This feature is directly related to the enhanced stability characteristics of the inventive aqueous hydrocarbon fuel compositions.
This invention further provides for an apparatus for making an aqueous hydrocarbon fuel composition, comprising: a high shear mixer; a blend tank; a chemical additive storage tank and a pump and conduit for transferring a chemical additive from said chemical additive storage tank to said blend tank; a conduit for transferring a hydrocarbon fuel from a hydrocarbon fuel source to said blend tank; a conduit for transferring a hydrocarbon fuel-additive mixture from said blend tank to said high-shear mixer; a water conduit for transferring water from a water source to said high-shear mixer; a fuel storage tank; a conduit for transferring an aqueous hydrocarbon fuel composition from said high-shear mixer to said fuel storage tank; a conduit for dispensing said aqueous hydrocarbon fuel composition from said fuel storage tank; a programmable logic controller for controlling: (i) the transfer of said chemical additive from said chemical additive storage tank to said blend tank; (ii) the transfer of said hydrocarbon fuel from said hydrocarbon fuel source to said blend tank; (iii) the transfer of said hydrocarbon fuel-additive mixture from said blend tank to said high shear mixer; (iv) the transfer of water from said water source to said high shear mixer; (v) the mixing of said hydrocarbon fuel-additive mixture and said water in said high shear mixer; and (vi) the transfer of said aqueous hydrocarbon fuel composition from said high shear mixer to said fuel storage tank; and a computer for controlling said programmable logic controller.
In one embodiment, the inventive apparatus is in the form of a containerized equipment package or unit that operates automatically. This unit can be programmed and monitored locally at the site of its installation, or it can be programmed and monitored from a location remote from the site of its installation. The fuel is dispensed to end users at the installation site. This provides a way to make the aqueous hydrocarbon fuels compositions prepared in accordance with the invention available to end users in wide distribution networks.
This invention also relates to an aqueous hydrocarbon fuel composition comprising: a continuous phase of a normally liquid hydrocarbon fuel; a discontinuous aqueous phase, said discontinuous aqueous phase being comprised of aqueous droplets having a mean diameter of 1.0 micron or less; and an emulsifying amount of an emulsifier composition comprising (i) a hydrocarbon fuel-soluble product made by reacting a hydrocarbyl-substituted carboxylic acid acylating agent with ammonia or an amine, the hydrocarbyl substituent of said acylating agent having about 50 to about 500 carbon atoms, (ii) an ionic or a nonionic compound having a hydrophilic lipophilic balance (HLB) of about 1 to about 10, or a mixture of (i) and (ii), in combination with (iii) a water-soluble salt distinct from (i) and (ii). In a preferred embodiment, component (i) is a combination of (i)(a) at least one reaction product of an acylating agent with an alkanol amine and (i)(b) at least one reaction product of an acylating agent with at least one ethylene polyamine. Preferably, component (i)(b) is combined with component (i)(a) in an amount from about 0.05% to about 0.95% based upon the total weight of component (i).